1. Field of the Invention
The present invention relates to a memory apparatus and a memory access restricting method that use a reversibly non-writable memory.
2. Description of the Related Art
A reversibly non-writable memory of which data can be written one time is known. For example, as a semiconductor memory, a so-called OTP (One Time Programmable) ROM in which data can be written one time has been proposed. The related art reference is a non-volatile reversibly non-writable memory. In other words, according to the related art reference, once data is written, it cannot be erased. Thus, even if the power of the memory is turned off, written data is retained. The reversibly non-writable memory can be fabricated at a lower cost than a flash memory.
Recently, the commercial use of card type flash memories as data record mediums tends to increase. For example, still pictures photographed by a digital camera are recorded to a flash memory. However, the cost of a flash memory is relatively high. In contrast, although the cost of a OTP is relatively low, it cannot be re-used as an adverse problem thereof. Thus, when the cost of an OTP is further decreased, it can be expected that it will be widely used. Generally, it is said that the cost of a device as a record medium is reversely proportional to the quantity placed on the market.
Therefore, an object of the present invention is to provide a memory apparatus and an access restricting method that allow a reversibly non-writable memory to be more widely used.
To solve the above-described problem, a first aspect of the present invention is a memory apparatus composed of a reversibly non-writable memory, comprising an initial data area to which initial data is pre-written, a user data area to which data prepared by the user is written, and a setup data area to which a setup state is written, wherein when data that is different from the initial data is written to said initial data area, said user area becomes non-accessible, and wherein when the used state of the memory is in the setup state, said user data area becomes accessible.
A second aspect of the present invention is a memory apparatus composed of a reversibly non-writable memory, comprising a first designated area to which initial data is pre-written, a user data area to which data prepared by the user is written, and a second designated area, wherein when predetermined data that is different from the initial data is written to said first designated area, said user data area becomes non-accessible, and wherein when data having a predetermined relation with predetermined data is written to said second designated area, said user data area becomes accessible.
A third aspect of the present invention is an access restricting method for a non-volatile reversibly non-writable memory apparatus, when predetermined data is written to a first designated area of the memory apparatus, the predetermined area being access-restricted, comprising the steps of detecting whether or not the memory apparatus has become access-restricted, causing the memory apparatus to be changed to an access restricted state when the memory apparatus has not been access-restricted, and causing the memory apparatus to be changed to an access permitted state when the memory apparatus has been access-restricted and the used state of the memory apparatus is in a predetermined state.
A fourth aspect of the present invention is an access restricting method for a non-volatile reversibly non-writable memory apparatus, when predetermined data is written to a first designated area, a predetermined area being access-restricted, comprising the steps of detecting whether or not the memory apparatus has been access-restricted, causing the memory apparatus to be changed to an access restricted state when the memory apparatus has not been access-restricted, and causing the memory apparatus to be changed to an access permitted state when the memory apparatus has been access-restricted and data written to a second designated area of the memory apparatus has a predetermined relation with the predetermined data.
According to the present invention, when a memory is used a predetermined number of times or when data that has a predetermined relation with particular data is written to a predetermined area of the memory, pre-written data can be accessed. The data may provide the user with a reward. Alternatively, the data may be advertisement/commercial information. Thus, the data will contribute to promote the promotion of the use of the memory apparatus, resulting in reducing the cost thereof.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.